Possible to make the bones visible when the mouse is hovering over a rigged model?
As far as I know there's currently no way to do it without coding a custom solution that will hide bones and only show them on mouse hover. This would actually be very cool if we had something like this as default on blender (with maybe a slider to customize mouse distance-to-bone activation, etc) but as of today we dont.

The best similar solution that I can think of is an addon that is called Skin Selection, unfortunately, it's paid.

https://www.blendernation.com/2017/09/18/add-skin-selection/

This is a video of it working:

https://www.youtube.com/watch?v=x8AOj-nDn2o

It allows you to select a bone by selecting the surface of the mesh as if it was the bone... and allows for multiple controllers to be assigned to similar regions of the mesh. So nothing gets in the way, every bone is hidden.

I have not bought it to experiment and say how hard it is to configure, or how automated it is, but I'd advise you to check it out, its not that expensive.